Ladder



May 10, 1949.

H. A. JOHNS I LADDER Filed Oct. 29, 1945 j ik J Patented May 10 1949 LAER:

of- Illinois arold A. Johns, Chicago, Ill assignor to Imagi; neer-ingCorporation, Chicago, Ill.; a corporation App ic ti n. October 29, .5Seria NQ- 2 ,33

(01. gas-a9) 4 Claims. 1

This invention relates to a ladder. and more particularly to a ladder ofa toldable type. The invention is particularly useful in connection witha foot ladder.

An object of the invention is to provide a ladder formed of relativelyfew parts and which may be readily folded into collapsed and expandedpositions, cooperating parts in the top portion of the ladder serving tolock the structure together into a sturdy rigid support when in expandedposition. A'further object is to provide a simple ladder structure whichmay be col p y s in e p eard. h dd r. and drawn to expanded position bymerely moving the rails of the ladder forwardly. the top. board of theladder serving not only as a handle for collapsing the ladder but also.when the lad-, der is in expanded position, serving to, lock thestructure rigidly supporting position, Other specific objects andadvantages will appear as the specification proceeds.

The invention is illustrated, in preferred embodiments, by theaccompanying drawing, in wh h. a

Figure l is a side view in elevation of a ladder embodying m invention;Fig. 2, a View similar to Fig. 1 but s owing the ladder in collapsedposition; Fig. 3, a rear view in elevation; Fig. 4, a top plan view; andFig. 5., a rearview irrelevation of the. ladder equipped with a modifiedform of back support. In the illustration given, a pair of side rails 10are connected by steps II and at their top engage a top board I2. A backsupport 13 is secured to the rear edge of the top board l2. Link members[4 connect the rails l0 and back support iii to limit the angle ofseparation thereof.

The side rails A may be formed of any suitable material andconfiguration. In the illustration given, the rail I0 is formed from astrip metal having rolled side edges l5 which provide tubular supportsand the intermediate web portion is preferably provided with elongatedopenings 16 which lighten the rails. Between theslots l6 cleats 11,formed of hollow metal webbing, are welded to the web portion of theside rails II] or otherwise secured thereto. The steps H are also shownformed of strips of metal having rolled edges l8 providing cross beamsupports and the members l8 are received within sockets provided by thecleats or step-supporting brackets IT.

The rails I!) are pivotally connected at their rear top edges at l9 tothe top board l2.

The top board I2 is preferably formed of metal having a wide central webportion 20 and dependins flan es. 2 Th W b p r ion. 2% is p e a lyprovided with ribs 22 or other suitable roughenl m If cle irfid. theforward corner pori ns of the web 2 nd n s 21. may be formed w resi iens t portions 2.3v wh c a e, daptd t ric iona y en ag and. grip. he o w rt p portion of the rails I'll.

The back support. [3. may be of any suitable construstion. In the formshown in Figs. 1 to 4 ncl ive. t c pris s a uvshsned ba h vi i t o n pota l qennectefd to the fl e Qfth r board. at 2.

Ph cosme ics of the back s p or 3 at 24 brings the back member in closerelation to the flange 2|, so that flange 2| is useful in praviding rigi i su p t o the back port at its 209-.

To limit the angle of separation between the back support 13 and therails Ill, I provide a link M which is pivotally connected to the backsuprest t and t the rails t 2.6.-

The rails 10 may beprqvided at their base with rubber inserts g1 whichprevent slipping of the rails, the inserts being secured within thetubu-v lar members l5 or many other way secured to the rails I0.

In he mQd fie qnstr etiq sh w in E the structure throughout is the sameexcept for h back. suppo t. he. bac suppor wn in Fig. 5 comprises a paircf members 118 having int rm d at po tions b wed inward a d secured et ea .9 b PQt W din belts or y o s er suitable means, the legs being sprungapart again at the bottom and provided with rubber bases 30.

In the operation of the structure, the ladder may be moved from thecollapsed position shown in Fig. 2 to expanded position by merelydrawing the rails l0 forwardly. This movement causes the top board l2 todrop to the position shown in Fig. 1 and the link l4 swings to theinclined position shown in Fig. 1. When the user steps upon the ladder,the ladder automatically locks itself rigidly by bringing the flange 2|tightly about the forward edges of the rails I0. If the sockets 23 areemployed, the sockets, which extend well around the forward portion ofeach rail I0 firmly grip the rail and lock it rigidly to the top boardl2.

After use of the ladder, the user may simply grasp the forward end ofthe board l2 and pull it upwardly. This movement causes the rails 10 toswing to the collapsed position shown in Fig. 2. The forward flange 2!serves, in these operations, not only as a locking element to providethe desired rigidity, but also as a handl for collapsing the ladder andcarrying the collapsed structure. It will be noted that in thisoperation no other manual movement is necessary. Since the link M is asingle member and is not formed of two pieces connected at their center,it is not necessary to brace the link in any manner.

While in the foregoing structure, I have set forth specific detailswhich are favored because of the new functions developed, it will beunderstood that changes may be made such as, for example, substituting atwo-link brace pivotally connected in the center for the one-link bracei4, and also other means may be provided for locking the rails to thetop board instead of the specific structure shown. I prefer, however,the specific structure illustrated because of the new functionsaccomplished, the extreme rigidity automatically provided by thepressure of a person upon the step in causing the flanges at top !2 togrip the rails, and the ease with which the structure may be collapsedthrough simply lifting the forward flange of board 12.

The modified form of back support 23 is extremely sturdy and firm whileemploying a relatively small amount of metal. The structure is furtherdesirable in that the diverging feet portions provide a means forself-centering the ladder when weight is put thereon.

While in the foregoing description, I have set forth certain detailsillustrating a particular embodiment of the invention, it will beunderstood that such details may be varied widely by those skilled inthe art without departing from the spirit of my invention.

I claim:

1. A ladder comprising a pair of rails, step means connecting saidrails, a back support, a top board having a web wider than said railsequipped with depending flanges, said flanges providing socket portionsadapted to grip the forward top portions of said rails when broughtthereagainst, means pivotally connecting the rear top portions of saidrails to said flanges at an intermediate point on said board to permitsaid rails to swing within said flanges and bring the forward topportions thereof into engagement with said flanges and permitting saidrails to swing rearwardly when the front portion of the board is raised,and means connecting the back support to the rear portion of said board.

2. A ladder comprising a pair of rails, step means connecting saidrails, a back support, a

top board having a web wider than said rails and equipped with dependingflanges, means con necting the rear top portions of said rails to saidflanges at an intermediate point on said board to permit said rails toswing within said flanges and bring the forward top portions thereofinto engagement with said flanges permitting said rails to swingrearwardly when the front portion of the board is raised, and meansconnecting the back support to the rear portion of said board.

3. A ladder comprising a pair of rails, step means connecting saidrails, a back support, a top board having a web wider than said railsand equipped with depending flanges, said flanges being adapted to gripthe forward top portions of said rails when brought thereagainst, meanspivotally connecting the rear top portions of said rails to said flangesat an intermediate point upon said board to permit said rails to swingwithin said flanges and bring the forward top portions thereof intoengagement with said flanges permitting said rails to swing rearwardlywhen the front portion of the board is raised, and means connecting theback support to the rear portion of said board.

4. A ladder comprising a pair of rails, step means connecting saidrails, a back support, a top board having a web wider than said railsand equipped with depending flanges, said flanges providing resilientsocket portions adapted to grip the forward top portions of said railswhen brought thereagainst, means pivotally connecting the rear topportions of said rails to said flanges at an intermediate point on saidboard to permit said rails to swing within said flanges and bring theforward top portions thereof into engagement with said flangespermitting said rails to swing rearwardly when the front portion of theboard is raised, and means connecting the back support to the rearportion of said board.

HAROLD A. JOHNS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,555,483 Rosenberg Sept. 29,1925 1,630,747 Johnson May 31, 1927 1,671,801 White May 29, 19282,15%,606 Covington Apr. 18, 1939

